I've tracked every fill-up I've EVER done since I bought the car. That means I've got 14 months of data spanning 24,400 miles, and 912.17 gallons of gas (costing $3,004.11) to draw from. Here's my information:
Avg MPG: 26.846
Min MPG: 18.324 (that was snow-storm shenanigans)
Max MPG: 33.979 (highway road trip)
Avg gal/fillup: 9.21
Avg mi/fillup: 246.8
I've noticed that the in-vehicle average readout is
consistently 1.5 MPG
HIGHER than what I am actually getting.
I live in Chicago. So my average will be lower than many because a lot of my time is spent in heavy traffic, or on streets with low speed limits and lots of traffic lights. When I'm driving on the highway, I tend to do somewhere between 70-80 MPH unless the speed limits are lower.
I have a 2015 Series.Blue, which is important to note because the underbody aero trays are good for a Cd of 0.27, as opposed to 0.28 for a limited (with the wing) or 0.29 for a wingless Toyobaru. This means I theoretically get slightly better highway mileage than most.
This driving was split between the OEM Michelin Primacy HP "low rolling resistance" tires during the warm months (mounted on the stock STi wheels, which weigh 18.4 lb, or ~2 lb less than the normal wheels), and General Altimax Arctic winter tires (205/55R16) mounted on very heavy steelies in the winter months.
I rarely spend much time above 4K RPM. I tend to shift between 3-4K.
One thing I did notice on my most recent road trip (which was on the winter tires) was that when the temperature was in the 30-50 degree range, I was only managing 29 MPG on the highway, whereas the second half of my trip occurred in 60-65 degree weather, and I got 33 MPG. A pretty big difference that one might attribute to the colder, denser air putting up more of a fight against a 78 MPH moving object.
Hope this info is interesting to some
